HI7106
and select VREF = 0.341V. Suitable values for integrating
resistor and capacitor would be 20kΩ and 0.22µF. This
makes the system slightly quieter and also avoids a divider
network on the input. Another advantage of this system
occurs when a digital reading of zero is desired for VIN ≠ 0.
Temperature and weighing systems with a variable fare are
examples. This offset reading can be conveniently generated
by connecting the voltage transducer between IN HI and
COMMON and the variable (or fixed) offset voltage between
COMMON and IN LO.
Typical Applications
The HI7106 may be used in a wide variety of configurations.
The circuits which follow show some of the possibilities, and
serve to illustrate the exceptional versatility of this A/D con-
verter.
Typical Applications
OSC 1 40
OSC 2 39
OSC 3 38
TEST 37
REF HI 36
REF LO 35
CREF 34
CREF 33
COMMON 32
IN HI 31
IN LO 30
A-Z 29
BUFF 28
INT 27
V - 26
G2 25
C3 24
A3 23
G3 22
BP 21
TO PIN 1
100kΩ
100pF
SET VREF
= 100mV
1kΩ 22kΩ
0.1µF
0.47µF
47kΩ
0.22µF
1MΩ
0.01µF
+
IN
-
+
9V
-
TO DISPLAY
TO BACKPLANE
OSC 1 40
OSC 2 39
OSC 3 38
TEST 37
REF HI 36
REF LO 35
CREF 34
CREF 33
COMMON 32
IN HI 31
IN LO 30
A-Z 29
BUFF 28
INT 27
V - 26
G2 25
C3 24
A3 23
G3 22
BP/GND 21
TO PIN 1
100kΩ
100pF
SET VREF
= 100mV
0.1µF
25kΩ 24kΩ
0.047µF
470kΩ
1MΩ
0.01µF
V+
+
IN
-
0.22µF
V-
TO DISPLAY
Values shown are for 200mV full scale, 3 readings/sec., floating
supply voltage (9V battery).
FIGURE 8. HI7106 USING THE INTERNAL REFERENCE
FIGURE 9. HI7106 RECOMMENDED COMPONENT VALUES
FOR 2V FULL SCALE
8